The invention relates to a dispenser for a foaming product.
After foaming products have been dispensed from a container, continued expansion of the product in a delivery conduit can cause the product to drool out of the discharge outlet.
Trotta U.S. Pat. No. 5,232,127 describes avoiding unwanted build-up of foamed product that continues to expand in and be discharged from a delivery conduit in a nozzle of a pressurized can after the valve has been turned off by using a cap that has an opening to permit uninhibited venting of gas entrained in the product in the conduit and entry of drying air to dry the product that has drooled from the nozzle after turning off the valve.
Ciaffone U.S. Pat. No. 3,917,121 describes providing an upwardly directed baffle in a discharge region to cause post-discharge foam to flow along the bottom surface of the baffle into a retraction chamber.
The invention features, in general, a foaming product that includes a container, a valve stem extending upward from the top of the container, a nozzle member, and a waste product containment region located above the top of the container. The valve stem is movable downward to permit discharge of the foaming product from the container through the stem. The nozzle member includes a flow passage for directing the foaming product from the top of the valve stem to a discharge outlet and a movable portion that is movable between a discharge position and an inactive position. When the movable portion is in the discharge position, the valve stem is actuated to permit discharge of product into the flow passage and out of the discharge outlet, and the flow passage does not communicate with the containment region. When the movable portion is in the inactive position, the valve is not actuated, and the flow passage communicates with the waste product containment region such that undischarged foaming product in the flow channel is directed to the waste product containment region.
Preferred embodiments of the invention may include one or more of the following features. In preferred embodiments the container is a pressurized can. The containment region is a substantially enclosed chamber. The dispenser includes a discharge shut-off structure that provides a waste flow path from the discharge outlet to the waste product containment region when the movable portion of the nozzle member is in the inactive position and permits the discharge outlet to discharge the foaming product when the movable portion of the nozzle member is in the discharge position. The shut-off structure can be stationary with respect to the container, and movement of the movable portion of the nozzle member from the discharge position to the inactive position causes the discharge outlet to be moved from a position outside of the waste flow path to a position where it communicates with the waste flow path. The movable portion of the nozzle member can be pivotally connected to the shut-off structure. The discharge shut off structure can wipe the discharge outlet as the movable portion moves from the inactive position to the discharge position.
The nozzle member can have a base portion that is connected to the container, and the movable portion can be pivotally connected to the base portion. A waste containment region can be located within the base portion underneath the movable portion.
In some preferred embodiments the flow passage includes a flow restriction that the foaming product overcomes when the valve stem is in the discharge position, and there is a waste flow diverter path from the flow passage to the waste product containment region when the movable portion of the nozzle member is in the inactive position, the waste flow diverter path having less flow resistance than the flow restriction when the movable portion of the nozzle member is in the inactive position so as to direct the undischarged foaming product to the waste product containment region, the waste product not overcoming the flow restriction when the movable portion is in the inactive position. The waste flow diverter path can be provided by a gap between the nozzle inlet and the top end of the valve stem when the movable portion of the nozzle member is in the inactive position, the nozzle inlet contacting a top end of the valve stem when the movable portion of the nozzle member is in the discharge position. The movable portion can be spring-biased to the inactive position. The flow restriction can be provided by a reduction in channel cross-sectional area of a flow passage in going from the nozzle inlet to the discharge outlet. Alternatively the flow restriction can be provided by a restricted area in the flow passage at the discharge outlet, e.g. the flow restriction can be provided by an insert placed in a flow passage at the discharge outlet.
The movable portion can be connected to the base portion by an integrally formed hinge between the base portion and the movable portion. The hinge can bias the movable portion to the inactive position. The movable portion can include first and second moving portions, the first moving portion having a flow passage therethrough and the discharge outlet thereon, the second moving portion being movably mounted with respect to the first portion such that the second portion closes the discharge outlet when movable portion is in the inactive position, and opens a discharge outlet when the movable portion is in the discharge position.
The waste product containment region can communicate with a chamber having a variable size, the chamber being operably connected to the nozzle member to have a decreased volume when the movable portion of the nozzle member is in the discharge position and an increased volume when the movable portion is in the inactive position. A decrease in pressure in the chamber (resulting from chamber expansion) is communicated to the flow passage to cause the waste product to flow from the discharge outlet and toward the waste product containment region after the valve has closed and the movable portion of the nozzle member has moved to the inactive position. The chamber can include a bellows. The nozzle member can include a guide member secured to the top of the can, and the nozzle member can have an extension that is telescoping with respect to the guide member as the movable portion of a nozzle member moves between the discharge position and the inactive position. The chamber can be spring-biased to the expanded position. The bellows can provide the spring biasing or a separate spring can be used.
Embodiments of the invention may include one or more of the following advantages. Foam product that expands in a flow passage conduit after discharge is prevented from drooling out of the discharge outlet and is instead directed to a waste product containment region and/or held inside the passage.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof and from the claims.